{ "number": 966, "headline": "June 23, 2026 Tuesday Summer Weather", "standfirst": "Heat dome to form across Southern US into early July with widespread 90s and 100s", "desk": "record", "dateline": { "place": "Weather Trader", "state": null, "lat": null, "lon": null, "site_key": null, "site_name": null, "site_url": null, "accent": null }, "edition": "2026-06-24", "published": "2026-06-24T02:01:34.065000Z", "updated": null, "access": "free", "body_html": "
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2 convective complexes over Texas

This is forecast post number 966: Day 174 of 2026. Day 23 of Atlantic Hurricane Season. Good Evening! Running very late with some unrelated computer problems, so I\u2019ll hit publish and come back to this by Noon on Wednesday. Thankfully, the weather across the Lower 48 is fairly quiet.

However, we need to start looking ahead to July and the formation of a powerful \u201cheat dome\u201d centered on Memphis, TN and baking the Southeast.

Author: Dr. Ryan Maue (X @RyanWeather X @weathertrader)

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Radar through 8:44 PM CT (earlier this evening)

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Watching a couple storm complexes moving along \u2014 dumping heavy rainfall.

NWS Precipitation Next 72-hours \u2014> Friday Evening

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Heavy rainfall will be focused on Kansas through Missouri, and into Illinois to Indianapolis with upgrades of 2\u201d to 4\u201d possible in just next few days.

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My favorite parameter \u2014 next 48-hours of HRRR Precipitable Water

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Weather Into Wednesday Morning

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HRRR Next 48-hours simulated Radar through Thursday 2 PM ET

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Weather on Wednesday \u2014 Cold front dips to the Gulf Coast

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Blend of Models \u2014> Precipitation Next 7-days

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Flagship model: ECMWF AIFS 18z \u2014> Integrated Vapor Transport next 10-days

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The magnitude of the tropical moisture feed into the USA from the Caribbean and Gulf is dialed down/back significantly as ridging strengthens over the Southeast U.S. \u2014> heat dome?

Update: Yes, we can see the anticyclonic turning of the ridge centered over the southern Mississippi River Valley with limited moisture transport \u2014> really going to heat up for early July.

ECMWF 18z | Precipitable Water | My Favorite Parameter

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Generally 1.8\u201d (yellow) PWAT with embedded > 2\u201d convective cells = heavy downpours across Central U.S. into the Southeast.

Temperature Analysis | RTMA | 8:45 PM ET

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About 34 million population at least 90\u00b0F at 8:45 PM ET but plenty of comfortable 60s and 70s blanketing the Lower 48 east of the Rockies.

Temperature Anomaly | RTMA | 8:45 PM ET

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Lower 48 was -1.7\u00b0F below normal behind the amazing cold front

High Temperatures Next 8-Days \u2014> Thursday July 2nd

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Trend to much hotter temperatures across the board into early July with 100s building across all of Texas with the much dryer conditions. Southeast including Atlanta and Carolinas push well into the 90s, and even 100s in the Carolinas.

With less tropical moisture plume activity from the Gulf of Mexico, we\u2019ll see much warmer temperatures and lower rain chances \u2014> warming trend into 4th of July.

239 million+ at least 90\u00b0F by July 1st with Lower 48 average high of 88.1\u00b0F

Low Temperatures on Wednesday

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High Temperatures on Wednesday

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Upper-Level Height Anomaly | AIFS-Single Next 10-days

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Very strong troughing digs into the Pacific Northwest in the medium range = much cooler across the Western U.S. with potential for mountain snow into early July.

Ridging builds across the Eastern U.S. \u2014> dry and heating up especially across the Southeast \u2014> HEAT DOME

Into Summer \u2014> Height Anomalies don\u2019t tell entire story \u2026 actual height helps!

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Same story as yesterday: 594 dm to 597 dm contours pop up across the U.S. border in AZ/NM and then in the Southeast \u2026 trending warmer \u2014> more typical \u201cheat dome\u201d centered over the Southeast into early July.

European Heat Dome | Temperature Anomaly next 12-days

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ECMWF Flagship Ensemble Mean Temperature Anomaly next 15-days

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Trough \u2014> cooler across the Pacific Northwest with huge negative anomalies of -20\u00b0F vs. the formation of a ridge into later June and HEAT across the Great Lakes and into the Mid-Atlantic + Canada

Week 1 \u2014> June 23 to June 29

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Week 2 \u2014> June 30 to July 6

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Pattern flip with trough in the NW and Western U.S. \u2014> cooler than normal with much warmer than normal into 4th of July east of the Rockies \u2014> trending HOTTER

Atlantic Basin \u2014 Very Quiet through end of June 2026

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Tropical Waves \u2026 multiple across the 2 basins but nothing active for certain in the Atlantic. These waves move into the Eastern Pacific but marginally favorable conditions (40%)

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Saharan Air Layer with African Dust \u2014 next 10 days

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During the months of June and July, winds over the African continent pick up sand and dust from the deserts and loft it into the boundary layer around 850-700 mb creating a stable and warm layer. The prevailing trade winds (east to west) in the tropics capture the dust layers and move them along into the Atlantic and eventually the Caribbean and even the Gulf of Mexico to provide beautiful & colorful sunsets for folks in Florida and Texas.

While the African dust plumes expected over the next 7-days aren\u2019t the most intense, NASA GEOS-5 shows a whopper in the Eastern Atlantic by early July.

Zooming out to North Africa \u2014 origin of the Saharan Air Layers + Sand/Dust

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Satellite Imagery \u2014 not much active convection across the entire Atlantic tropics

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Ensemble Storm Tracks Next 15-days \u2014> Complete Ghost Town in Atlantic

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2 Tropical Waves in Eastern Pacific with Medium Chance (40%) in coming week

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Western Pacific Typhoon Season

Typhoon Mekkhala BLEW a tire \u2026 almost sheared complete part with strong northerly wind shear decoupling the low level circulation from the convection. Tough break!

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We\u2019ll see if the wind shear relaxes, or else this storm may struggle to regain convection, and be a large remnant low.

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Tropical Depression Higos (08W) will become a weak tropical storm. No threat to land but it will come close to Japan.

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Full Physics ECMWF Ensembles | Next 15-days | Active Storm Tracks

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Long track, powerful Typhoon coming out of the far eastern part of the basin near the Dateline is typical of El Ni\u00f1o summers \u2014> Lots of ACE

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My Atlantic Hurricane Season Forecast (2026)

From April 7, 2026: Atlantic Seasonal Hurricane Forecast: (11/5/2)

9-13 Named Storms (11 most likely)
4-7 Hurricanes (5 or 6 most likely)
1-3 Major Hurricanes (2 most likely)
Accumulated Cyclone Energy: 75-85 (well below normal)

NOAA 2026 Atlantic Hurricane Season Forecast

More details in Thursday, May 21, 2026 Tropical Update

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However, we need to start looking ahead to July and the formation of a powerful \u201cheat dome\u201d centered on Memphis, TN and baking the Southeast.

Radar through 8:44 PM CT (earlier this evening)

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